In the prior art, there already exist numerous documents that describe fastener rings for fastening a pump or a valve on a reservoir neck. The fastener means for fastening the ring may use various known techniques, e.g. such as screw-fastening, crimping, snap-fastening, etc. In the snap-fastening technique, there exist two distinct types, namely snap-fastening performed only by the fastener ring, and snap-fastening performed by the fastener ring co-operating with a locking hoop that comes to surround the ring. The crimping and snap-fastening techniques make it possible to provide fastening that is permanent, in the sense that the user does not normally need to remove the pump from the reservoir. The screw-fastening technique provides fastening that is not permanent, enabling the user to unscrew the ring so as to be able to access the inside of the reservoir via the neck. The invention finds an advantageous application with permanent fastener rings, but could also be applied to non-permanent fastener rings if that turns out to be necessary or useful.
Increasingly, it is required to be able to recycle the dispenser, i.e. to be able to separate the various component elements for the purpose of recycling them separately. Naturally, when the fastener ring provides fastening that is permanent (by crimping or by snap-fastening), removing the dispenser is complicated since it requires the fastener ring to be destroyed, which often turns out to be complicated. With screw-fastener rings, the problem exists only in restricted manner, given that it is possible to unscrew the ring from the neck. However, in some applications, it may be desirable to be able to remove the ring without having to unscrew it. Unfortunately, that is not possible with conventional fastener rings that are currently on the market.